There is growing concern that biological infectious waste streams from hospitals, slaughter houses, and other sources that may contain biologically hazardous or toxic components are not adequately treated before discharging such waste streams to sanitary sewer systems or directly to the environment. Large municipal treatment facilities may not adequately be configured for high concentrations of biological materials originating in hospitals and other sources. Accordingly, there is a need for improved systems and methods for treating waste streams before the streams are discharged into a sanitary sewer system or directly to the environment. There is also a need for modular systems that may be readily deployed into an existing sanitary sewer system at the source of the waste stream thereby reducing the degree of infectivity of the material a municipal system must treat.
In view of the foregoing and other needs, an exemplary embodiment of the disclosure provides a modular waste disinfection system for substantially liquid infectious waste streams and methods of treating such waste streams. The modular waste disinfection system may include a metal ion generation chamber for introducing metal ions into the waste material; an oxidant generation chamber in fluid flow communication with the metal ion generation chamber for disinfection of the waste material with an oxidizing agent; and a chelation chamber in fluid flow communication with the oxidant generation chamber for deactivation of metal ions in the waste material.
Another exemplary embodiment of the disclosure provides a method of treating a sanitary sewer waste material to provide a treated waste stream. The method may include flowing a waste stream from a sanitary sewer drain into a modular waste disinfection system. The modular waste disinfection system may include a metal ion generation chamber for introducing metal ions into the waste material to partially disinfect the waste material; an oxidant generation chamber in fluid flow communication with the metal ion generation chamber for disinfection of the waste material with an oxidizing agent; and a chelation chamber in fluid flow communication with the oxidant generation chamber for deactivation of metal ions and oxidation chemicals in the waste material.
According to the method, the waste stream may be macerated to a predetermined particle size and may be contacted with a film inhibitor and/or a foam inhibitor in the maceration chamber. Metal ions may be generated in situ in the metal ion generation chamber for contact with the waste stream from the maceration chamber to disinfect the waste stream. The waste stream may be oxidized in the oxidant generation chamber by oxidants generated in situ, in order to eliminate any biological activity in the waste stream. The metal ions in the waste stream may then be chelated in the chelation chamber in order to sequester and deactivate any remaining metal ions and oxidizing chemicals present in the waste stream before discharging the treated waste stream into a sanitary sewer or directly to the environment.
An advantage of the system and methods described herein is that the system combines at least two disinfection techniques in a single unit thereby increasing the effectiveness of waste stream disinfection over the use of a single disinfection technique. Unlike conventional systems, the active disinfection ingredients are deactivated prior to the waste stream being discharged from the disinfection unit so that the disinfection ingredients and waste stream may be discharged to the sanitary sewer system or directly to the environment without removing the disinfection ingredients from the waste stream. Because of the modular components of the system, the system may be configured as a mobile, or portable, stand-alone unit or may be provided in a substantially fixed non-portable installation that may be inserted between a waste material source and a final disposition of the waste material. The waste treatment system may also be combined and/or integral with a waste collection system or may be configured as a stand-alone system for discharge directly to the environment.
Additional objects and advantages of the disclosure are set forth in part in the description which follows, and/or may be learned by practice of the disclosure. The objects and advantages of the disclosure may also be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure, as claimed.